Method of recognizing touch

ABSTRACT

The disclosure relates to a method for recognizing touch. A first value T 1  and a second value T 2  are set. A maximum sensing value C peak  is obtained. A position of the C peak  is defined as a sensing position A. Sensing values C 1 , C 2 , C 3 , and C 4  of four neighboring sensing positions are obtained. C peak  is compared with T 1  and T 2 . When C peak  is greater than or equal to T 1 , a touch with finger is recognized. When C peak  is smaller than T 2 , no touch is recognized. When C peak  is greater than or equal to T and smaller than T 1 , following steps are taken. A third value T 3  is set. A first total sensing value C t  of C 1 , C 2 , C 3 , and C 4  is compared with T 3 . When C t  is greater than or equal to T 3 , a touch with glove is recognized. When C t  is less than T 3 , no touch is recognized.

This application claims all benefits accruing under 35 U.S.C. §119 fromChina Patent Application No. 201310314149.2, filed on Jul. 25, 2013 inthe China Intellectual Property Office, the contents of which are herebyincorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a method of recognizing touch on atouch panel and particularly a method of recognizing touch on acapacitive touch panel.

2. Description of Related Art

In recent years, various electronic apparatuses such as mobile phones,car navigation systems have advanced toward high performance anddiversification. There is continuous growth in the number of electronicapparatuses equipped with optically transparent touch panels in front oftheir display devices such as liquid crystal panels. A user of suchelectronic apparatus operates it by pressing a touch panel with a fingeror a stylus while visually observing the display device through thetouch panel.

According to working principle and transmission medium, touch panel hasfour types of resistance, capacitance, infra-red, and surfaceacoustic-wave. Capacitive touch panel has been widely used for itshigher sensitivity and lower touch pressure required.

Working principle of capacitive touch panel is as follows: distributionof capacitance on the touch panel is changed by a finger touch, thechange of distribution of capacitance is detected and a touch positionis obtained. However, if the finger is coated by an insulator such asgloves, the touch cannot be recognized, thereby causing inconvenience tousers.

What is needed, therefore, is a method of recognizing touch that canovercome the above-described shortcomings.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with referencesto the following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the embodiments. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a structure view of a touch panel.

FIG. 2 is a flowchart of a method of recognizing touch on a touch panel.

FIG. 3 is a view of signal values of a touch panel detected by anintegrated circuit (IC).

DETAILED DESCRIPTION

The disclosure is illustrated by way of example and not by way oflimitation in the fingers of the accompanying drawings in which likereferences indicate similar elements. It should be noted that referencesto “an” or “one” embodiment in this disclosure are not necessarily tothe same embodiment, and such references mean at least one.

The method of recognizing touch can be applied on all kinds ofmutual-inductance capacitive touch panels. Referring to FIG. 1, amutual-inductance capacitive touch panel comprises a driving layer 12, asensing layer 14, and an integrated circuit (IC). The IC is electricallyconnected with the driving layer 12 and the sensing layer 14. Thedriving layer 12 is spaced from and opposite to the sensing layer 14.

The driving layer 12 comprises a plurality of driving electrodes 120.The plurality of driving electrodes 120 are spaced from each other andextend along an X direction. The sensing layer 14 comprises a pluralityof sensing electrodes 140. The plurality of sensing electrodes 140 arespaced from each other and extend along a Y direction. The X directionis substantially perpendicular to the Y direction. The plurality ofsensing electrodes 140 are insulated with the plurality of drivingelectrodes 120. The plurality of sensing electrodes 140 intersect withthe plurality of driving electrodes 120 to define a plurality of sensingpositions. A plurality of mutual-inductance capacitance can be formedbetween the plurality of sensing electrodes 140 and the plurality ofdriving electrodes 120. In one embodiment, the plurality of sensingelectrodes 140 are parallel with each other and the plurality of drivingelectrodes 120 are parallel with each other The plurality of sensingelectrodes 140 and the plurality of driving electrodes 120 arestrip-shaped electrodes. Material of the plurality of sensing electrodes140 and the plurality of driving electrodes 120 can be indium tin oxideor carbon nanotube.

The plurality of driving electrodes 120 are labeled by an m in order.The m is a natural number. The IC comprises a driving IC and a sensingIC. The driving IC is electrically connected with the plurality ofdriving electrodes 120. The driving IC is used to provide drivingsignals to the plurality of driving electrodes 120. The sensing IC iselectrically connected with the plurality of sensing electrodes 140. Theplurality of sensing electrodes 140 are used to detect signal values viathe plurality of sensing electrodes 140.

Referring to FIG. 2, the method of recognizing touch comprises followingsteps:

S1, setting a first value T₁ and a second value T₂, wherein the secondvalue T₂ is smaller than the first value T₁;

S2, sensing touch signals and obtaining a maximum signal value C_(peak),defining a position of the maximum signal value C_(peak) as a sensingposition A, and obtaining signal values C₁, C₂, C₃, and C₄ of foursensing positions adjacent to the sensing position A;

S3, comparing the maximum signal value C_(peak) with the first value T₁and the second value T₂, when the maximum signal value C_(peak) isgreater than or equal to the first value T₁, recognizing as a touch withfinger; when the plurality of first signal values C₁ is smaller than thesecond value T₂, recognizing as no touch; and when the plurality offirst signal values C₁ is greater than or equal to the second value T₂and smaller than the first value T₁, further taking following steps;

S4, setting a third value T₃;

S5, defining a first total value C_(t) of the first maximum signal valueC_(peak) and the signal values C₁, C₂, C₃, and C₄, and comparing thefirst total value C_(t) and the third value T₃, when the first totalvalue C_(t) is greater than or equal to the third value T₃, recognizingas a touch with glove; and when not, recognizing as no touch.

In step (S1), the first value T₁ can be a threshold value of sensingsignal of a traditional capacitive touch panel. In one embodiment, amaximum signal value is sensed by the sensing IC when the fingercompletely contacts the touch panel, and the first value T₁ is definedas one fifth to one third times of the maximum signal value.

In one embodiment, the second value T₂ is greater than a backgroundsignal value. The background signal value is a parasitic capacitancewith no touch. The background signal value is caused by conductive wiresconnecting with the IC.

In step (S2), the plurality of sensing electrodes 140 intersect with theplurality of driving electrodes 120 and the plurality of sensingpositions are formed. In one embodiment, a coordinate of the sensingposition A is defined as (X_(A), Y_(A)), and coordinates of four sensingpositions adjacent to the sensing position A are defined as (X_(A−1),Y_(A)), (X_(A+1), Y_(A)), (X_(A), Y_(A−1)), and (X_(A), Y_(A+1)).

The plurality of driving electrodes 120 are driven by the driving IC.The plurality of driving electrodes 120 can be driven one by one inorder, or some of the plurality of driving electrodes 120 are drivensimultaneously each time. Signal value is a difference value betweensignal values at one position of the touch panel when the touch panel istouched and not touched.

In step (S3), when the plurality of first signal values C₁ are greaterthan or equal to the second value T₂ and smaller than the first valueT₁, the following step (S4) to step (S5) are taken in order to recognizewhether it is no touch or a touch with glove, and not to be recognizedas no touch directly.

In step (S4), a second maximum signal value C′ is sensed by the sensingIC when the finger with glove completely contacts a sensing position Bof the touch panel. A second total value C″ is defined by adding thesecond maximum signal value C′ and four signal values of four sensingpositions adjacent to the sensing position B. The third value T₃ isdefined to one fifth to one third times of the second total value C″.

In step (S5), the touch with glove means an insulator such as the gloveis existed between the screen and the finger. It is further determinedwhether it is the touch with glove by comparing the total value C_(t)with the third value T₃. When the total value C_(t) is smaller than thethird value T₃, it is determined that the finger has a long distancewith the screen or the background signal is recognized. When the totalvalue C_(t) is greater than or equal to the third value T₃, it isdetermined as the touch with glove.

“False touch” means that the finger does not touch the screen actuallyand is just near the screen. When the distance between the screen andthe finger is about a thickness of glove, the sensing IC would sensethis “false touch.” If the touch is the “false touch”, the finger couldnot keep static during the time period and would move away from thescreen. Therefore, following substeps (S31) to (S34) are further takenbefore step (S4) in order to prevent recognizing as the “false touch”:

S31, setting a time period;

S32, driving the plurality of driving electrodes 140 several times andsensing a plurality of third signal values during the time period;

S33, selecting a maximum signal value C′_(peak) from the plurality ofthird signal values of each time to obtain a plurality of maximum signalvalues C_(1peak), and calculating an averaged signal values C′_(peak) ofthe plurality of maximum signal values C′_(peak), when the plurality ofmaximum signal values C′_(peak) satisfy following formula: 0.8 C′_(peak)≦C′_(peak)≦1.2 C′_(peak) , going to the steps (S4) to (S6); and whennot, recognizing as no touch.

In step (S31), the time period ranges from one second to four seconds.

In step (S32), the plurality of driving electrodes 140 is driven one byone each time.

In step (S33), the touch can be two types of fixing and sliding. Thefixing touch means the finger touches on a same position during the timeperiod, and the plurality of maximum signal values C′_(peak) areequivalent. The sliding touch means the finger moves on the screenduring the time period, and the plurality of maximum signal valuesC′_(peak) change with touching positions.

When the finger touches a position of one of the plurality of sensingelectrodes 140, the signal value is great; when the finger touches aposition between adjacent two of the plurality of sensing electrodes140, the signal value is small. Therefore, the maximum signal valuesC′_(peak) of several times are obtained and the averaged signal valuesC_(peak) of the plurality of maximum signal values C′_(peak) of severaltimes are calculated.

The method of recognizing touch has following advantages. Both the touchwith finger and the touch with glove are recognized via this method.Some other errors of recognizing touch by mistake could be excluded.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present embodiments have been setforth in the foregoing description, together with details of thestructures and functions of the embodiments, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the disclosure.

What is claimed is:
 1. A method of recognizing touch on a touch panel,wherein the touch panel comprises a plurality of driving electrodes anda plurality of sensing electrodes, the plurality of driving electrodesintersect with the plurality of sensing electrodes to define a pluralityof sensing positions, and the method comprising: setting a first valueT₁ and a second value T₂, wherein the second value T₂ is smaller thanthe first value T₁; sensing touch signals and obtaining a maximum signalvalue C_(peak), defining a position of the maximum signal value C_(peak)as a sensing position A, and obtaining signal values C₁, C₂, C₃, and C₄of four sensing positions adjacent to the sensing position A; comparingthe maximum signal value C_(peak) with the first value T₁ and the secondvalue T₂, when the maximum signal value C_(peak) is greater than orequal to the first value T₁, recognizes as a touch with finger; when theplurality of first signal values C₁ is smaller than the second value T₂,recognizes as no touch; and when the plurality of first signal values C₁is greater than or equal to the second value T₂ and smaller than thefirst value T₁, taking following steps; setting a third value T₃;defining a first total value C_(t) of the maximum signal value C_(peak)and the signal values C₁, C₂, C₃, and C₄, and comparing the first totalvalue C_(t) and the third value T₃, when the first total value C_(t) isgreater than or equal to the third value T₃, recognizes as a touch withglove; and when the first total value C_(t) is less than the third valueT₃, recognizes as no touch.
 2. The method of claim 1, wherein the firstvalue T₁ is defined as one fifth to one third times of a maximum signalvalue of sensing when a finger completely contacts the touch panel. 3.The method of claim 1, wherein the second value T₂ is greater than abackground signal value.
 4. The method of claim 1, wherein a secondmaximum signal value C′ is sensed when the finger with glove completelycontacts a sensing position B of the touch panel, a second total valueC″ is defined by adding the second maximum signal value C′ and foursignal values of four sensing positions adjacent to the sensing positionB, and the third value T₃ is defined as one fifth to one third times ofthe second total value C″.
 5. The method of claim 1, further comprisingfollowing steps before setting the third value T₃: setting a timeperiod; driving the plurality of driving electrodes several times andsensing a plurality of third signal values during the time period; andselecting a maximum signal value C′_(peak) from the plurality of thirdsignal values of each time to obtain a plurality of maximum signalvalues C_(1peak), and calculating an averaged signal values C′_(peak) ofthe plurality of maximum signal values C′_(peak), when the plurality ofmaximum signal values C′_(peak) satisfy following formula: 0.8 C′_(peak)≦C′_(peak)≦1.2 C′_(peak) , going to the step of setting the third valueT₃; and when not, recognizes as no touch.
 6. The method of claim 5,wherein the time period ranges from one second to four seconds.